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Soil aggregates are an important controlling factor for the physico-chemical and biological processes such as ammonium (NH4+) retention. Straw return to the field is increasingly recommended to promote soil carbon (C) sequestration and improve crop yields. However, the effects of straw return on NH4+ retention at soil aggregate level in agricultural soils have seldom been investigated. This study aimed to evaluate the influences of long-term straw return on NH4+ adsorption and fixation in microaggregates (

The detection and classification of transient signals are widely applied in many fields of power system. The study of transient signal detection and classification is a sustaining focus of researchers as well as a difficult issue. There are still many problems needed to be solved in this area. Based on the wavelet transform (WT), the idea of entropy and weight coefficient is introduced, and the wavelet energy entropy (WEE) and wavelet entropy weight (WEW) are defined in this paper. The distribution picture of WEE and WEW along with scales are presented for the first time. PSCAD/EMTDC models for six types of transients, namely breaker switching, capacitor switching, short circuit fault, primary arc, lightning disturbance and lightning strike fault, are constructed. With WEE and WEW, the eigenvectors for the six transients are established and a model which uses the eigenvectors as the input of the BP (back-propagation) neural network is set up to realize the classification of these transients. The simulation has been executed based on a 500 kV transmission line model in China and the results show that feature extraction based on WEE and WEW can effectively discover the useful local features. With the help of neural network classifier, it has effective classifying result. This method is applicable in the power system.

The bone marrow microenvironment protects leukemia cells from drug-induced damage, and cell adhesion-mediated drug resistance (CAM-DR) is the main obstacle for the eradication of bone marrow minimal residual disease. In this study, we evaluated the survival response of K562 cells co-cultured with bone marrow stromal cells (BMSCs) derived from patients with chronic myelogenous leukemia (CML). Co-cultured K562 cells had a survival advantage after exposure to cytotoxic drugs compared to suspended K562 cells, but there was no survival difference between the two groups following exposure to As(2)O(3). The cytotoxicity of As(2)O(3) combined with cytotoxic drugs had an additive effect in the suspension group and a synergistic effect in the co-cultured group. Similar apoptotic responses were found using flow cytometry assays. As(2)O(3) treatment caused a dose dependent reduction of the adhesion ability of K562 cells to BMSCs, and Western blot analysis revealed that the treatment of K562 cells with As(2)O(3) led to down-regulation of beta(1)-integrin.